Using caulking and weather stripping in your home can help to reduce air leaks, which means more warm air stays inside when it's cold outside. While both products seal air leaks, they're used in different ways.
Caulk is used when you want a flexible seal around cracks or joints (less than 1/4-inch wide), such as around windows and door frames, plumbing fixtures and pipes, and even ceiling fixtures. Weather stripping should be used around movable joints, including windows and doors.
Check for leaks around pipes, electrical outlets and vents. Look closely under sinks, around vents and in closets. Find a gap? Plug it up and the U.S. Department of Energy estimates you'll reduce your heating and cooling costs by up to 30 percent.